The value of Korean, American, and Chinese ultrasound risk stratification systems combined with BRAF(V600E) mutation for detecting papillary thyroid carcinoma in cytologically indeterminate thyroid nodules

Purpose To investigate the value of Korean, American, and Chinese ultrasound risk stratification systems combined with BRAF(V600E) mutation in the detection of papillary thyroid carcinoma (PTC)within cytologically indeterminate thyroid nodules (CITNs).Methods A single-center retrospective study encompassed 511 CITNs selected from 509 patients between January 2020 and July 2023.Each nodule underwent surgical treatment and was classified according to three distinct systems. Receiver operating characteristic (ROC) curves were plotted using histopathological diagnosis as the reference standard, and diagnostic performance was compared.Results The three ultrasound stratification systems showed an elevated malignant risk with increasing grades (all P for trend2 < 0.001). The cut-off values for Korean, American, and Chinese systems were 5, 5, and 4c, and their respective area under the curves (AUCs) were 0.735, 0.778, and 0.783.The combination of BRAF (V600E) mutation significantly enhanced the diagnostic efficacy for the Korean(0.773vs0.735, P < 0.001), American (0.809vs0.778, P < 0.001) and Chinese (0.815vs0.783, P < 0.001) stratification systems in distinguishing CITNs without compromising specificity. When the three stratification systems were applied individually or combined with BRAF (V600E) mutation, the AUCs of the American and Chinese systems were similar (all P > 0.05), both of which were higher than the AUC of the Korean system (all P < 0.05). The American system exhibited higher specificity compared to the Chinese and Korean systems (all P < 0.001), whereas the Chinese system demonstrated higher sensitivity and accuracy when compared to the American and Korean systems (all P < 0.001).Conclusion Korean, American and Chinese stratification systems present potential in the differential diagnosis of CITNs. BRAF (V600E) mutation can significantly improve the detection rate of malignant nodules within CTNs, particularly PTC. Notably, the American and Chinese systems demonstrate superior overall diagnostic performance among these systems.